1. Field of the Invention
The present invention relates to a mutual connecting apparatus between networks within a factory in which electric devices such as programmable logic controllers and computers are connected to each other through networks.
2. Description of the Related Art
In general, a mini manufacturing automation protocol (which is called miniMAP in the following description) is a network within a factory developed such that programmable logic controllers, computers, numerical controllers, etc. within the factory are connected to each other through the network and can be operated in cooperation with each other. This protocol is standardized by a public governing system.
A mechatronics network (which is called ME-NET in the following description) is also a network within a factory constructed such that programmable logic controllers, computers, numerical controllers, etc. within the factory are connected to each other through the network. This network is used in many factories, but no protocol of this network is standardized by a public governing system.
The above miniMAP can identify each of connected devices by a Media Access Control address (which is called a MAC address in the following description) of 6 bytes and a Local Service Access Point address (which is called a LSAP address in the following description) of one byte. The above ME-NET can identify each of 64 connected devices at its maximum by a station address of one byte. Recently, various networks within a factory have been used as factory automation (FA) is advanced. Simultaneously, requirements for control of decentralized networks by connecting them together have been also increased.
A plurality of general ME-NETs independently used so far can be controlled by a programmable logic controller in one of these ME-NETs, when the ME-NETs are connected mutually or each of these ME-NETs is connected to a general miniMAP. However, the miniMAP and each of these ME-NETs cannot be mutually connected to each other since address restrictions and systems are respectively different from each other. Namely, the address systems of the above general miniMAP and ME-NET are greatly different from each other so that no connected device can be uniquely identified. Therefore, it is impossible to transmit and receive data between the miniMAP and the ME-NET by mutual connection.